For everyone who doesn’t drive to work, public transportation has always been the best option. But what happens when the price of mass transit increases, and services are cut?

The answer: illegal commuter vans.

The number of unlicensed and otherwise illegal vans offering cheap rides to residents in neighborhoods that lack adequate mass transit services has risen in recent years.

Though reliable statistics on the exact amount of illegal vans in operation don’t exist, riders, city officials and transportation advocates agree the industry has grown into a major concern under the Bloomberg Administration.

It’s not a coincidence that this has coincided with several remarkably bad years for the MTA. (Multiple fare hikes, a transit strike, a massive budget deficit and this year’s service cuts come to mind).

As the MTA’s woes continue to build, it's no wonder demand has risen for alternative forms of transportation. And in a city full of innovative entrepreneurs, the rise in profitable illegal commuter van companies is no surprise, either.

The problem facing the city now is how to regulate the industry. Of course, many commuter vans are licensed and ply legal, mapped-out routes. But many do not, choosing to work in the dark in the hopes of avoiding detection in order to make fast and easy cash.

A city-run pilot program announced last month will offer $2 rides along bus routes that were cut to help plug the MTA shortfall.

They include routes through Flushing, Kew Gardens, Park Slope, and Carroll Gardens. Riders will be able to get on and off at requested stops. The service will begin later this month.

It’s a good idea, and for riders of eliminated bus lines like the Q74 and B71 the city’s Group Share rides are certainly better than nothing.

But here’s the problem: unless the city expands the program to cover all five boroughs, people without the service will start feeling underserved, whether they have access to mass transit or not, for the simple reason that the Group Share rides are cheaper than the MTA’s fares.

And what’s to say the city can afford to operate the program for the foreseeable future? These days, no public services can or should be taken for granted.

And unless the private commuter van industry is effectively regulated, there is little reason to think people will opt for the city program over less-expensive neighborhood companies they already know and trust.

A new City Council bill would help enforce the regulation of illegal commuter vans. In New York City, however, that could be easier said than done. Illegally or not, people have to get to work.